This invention relates to a contact and a connector comprising the contact.
As an elastic contact for use in a ground/signal/antenna connection connector or a card connector for a digital device such as a smartphone, there is known a structure as described in JP-A-2014-35835 (Patent Document 1) in which, in order to achieve miniaturization of a contact while maximizing its spring length, two types of plate springs are placed side by side and joined together and an end portion of only one of the plate springs is fixed to a board of a digital device.
In such a structure, however, in order to design the properties as a spring such as a contact force and a displacement amount when a connection object is in contact with the contact, the balance of forces of the two types of plate springs should be strictly designed as described in, for example, JP-A-2014-75332 (Patent Document 2).
This point will be described with reference to FIG. 12. As shown in FIG. 12, a contact 30 of Patent Document 2 comprises a fixing portion 31 fixed to a connector body 10, a first spring portion 33 provided in a rectangular annular shape and elastically deformable relative to the fixing portion 31, a second spring portion 34 projectingly provided on the inner peripheral side of the first spring portion 33 and elastically deformable relative to the first spring portion 33, and a contact portion 35 provided at a free end of the second spring portion 34.
With this structure, when a connection object such as a card is pressed against the contact portion 35, the contact portion 35 is pushed down toward the board 3 side, while an opposite side portion 33A or a joining portion 37 rises, so that the first spring portion 33 and the second spring portion 34 are elastically deformed.
Herein, in order to balance the forces of the first spring portion 33 and the second spring portion 34 as the two types of plate springs, the contact 30 is designed so that the spring stiffness of the first spring portion 33 and the spring stiffness of the second spring portion 34 are equal to each other. Specifically, a value twice the width of each of lateral side portions 33B of the first spring portion 33 and a value of the width of the second spring portion 34 are approximate to each other.